Maybe I caused this somehow. I did edit a few things in the database. But I added a tag to a post using the cumminity tagging feature, it had a comma in it as I thought I could add two tags at once. Then I added another tag. Then I deleted the status messages under the post about the two new tag edits and the terms table in the database is filling up with the tags from the first attempt but as two separate database entries as if it was split on csv. It is up to 8000 records now, when it started at 240

I can cause it to happen on the same RSS source but it doesn't happen on a different RSS source. The post didn't have any tags, I added #rpg to it, all was ok, I deleted the status update and then the database started filling up the terms table again - but it fills it up with the tags assigned during RSS source import. I didn't have those tags set before the post was created, so the post had emtpy tags, then I changed the source import settings to have tags and now things are weird.

I've managed to make it happen on a fresh install from the dev branch, But whether I caused it by manually deleting entries from terms table or not is still not conclusive. I will have to do another test on a fresh install now that I almost know all the steps to do, will report back tomorrow.

do not do this on a used database.- set users as Forum Mostly Public- set admin/allow community tagging- add rss feed as connection- add New Source of feed with a tag eg "test"- delete RSS connection, add it again to get a fresh version of the posts with tags (so we can comment on post, otherwise is locked?)- click recent activity from connections for RSS connection- click "view in context" on a post to see the comment field - either make a comment with any hash tag (or maybe needs to match). then delete that comment with the hashtag.or add a tag, then delete the status- check Database is looping. CPU use is 100%

I don't know if it happens for non-RSS I should check that...

idea: one way to fix the table of any hubs which have had this happen (which could be any with rss and source!) is set UNIQUE contstrain using all fields except tid and term_hash, since you'd never need more than 1 of the same row anyway but I dunno if term_hash and parent_hash are used need expert here.ALTER IGNORE TABLE term ADD UNIQUE( aid, uid, oid, otype, ttype, term, url, imgurl, parent_hash);

When we start multiple delivery chains, we set a 'source_xchan' to point to where this message originated. In this case the forum delivery is setting it to one thing and the feed republish is setting it to something else - on the same item. Both of these actions create a fork in delivery (aka "multiple delivery chain") but they behave differently in the way these forked deliveries are managed. The end result is total confusion about how to deliver this sucker. Adding and removing tags and comments all interact with the same delivery system and these actions aren't that relevant in themselves - they merely compound the confusion and ensure total chaos occurs once things start to go wrong. The only solution I can offer is to remove either the forum or the feed republish from creating this conflict in the first place. They work pretty well on their own but there's really no way they will ever work together.

@Mike Macgirvin bummer. Using RSS feeds as a source in forums is a very handy feature I think. As long as the RSS feed could still exist as a separate non-forum "feed republish" channel and be sourced into the forum as a normal "connection" I think it's fine. I just avoiding creating mine as dedicated separate channels because it is less effort, though now I see how that should probably be removed and fix up the existing hub databases if needed (unique constraint sql will do it AFAIK ;) ).

After some testing I am pretty sure (as @Mike Macgirvin said) there is no combination of RSS "Channel Sources" posts and Forum type Channel that is safe to use with RSS+tags. No matter if the Connection + "Channel Sources" uses Republish as Author or not there are still extraneous Terms entries created by the thousand in the Terms DB table. This means that a forum cannot use "Channel Sources" if the Connection has ANY posts coming from an RSS feed in the chain. I am not 100% certain on this as I am still new to this and my testing is fairly messy.

But the bug only shows up when a comment attached to an RSS "sourced" post is deleted. Otherwise things might appear to be working until BAM, CPU spike and database garbage.